Until this year I had a restored 2hp Seagull forty plus ( probably in reality more like 1 hp ) mounted on a proper transom clamp. Worked fine, looked beautiful all polished up, cost very little, weighed even less and moved the boat along though not very swiftly and I’m sure would have struggled against even a modest tide but as I only used it on the Broads that wasnt much of an issue. It was a bit smokey as all these are and always dripped and made rainbow pools on water which I didnt think was very environmentally friendly but the biggest problem was that there was no way of preventing the rudder getting spiked by the prop and it took chunks out on several occassions; I was always a bit wary of all those whirring bits from a safety perspective and the possibility of dropping the starting cord over the side too.
I looked at getting a Honda 4 stroke to be quieter but they are physically enormous and ther thrust per pound weight and cost were not attractive either. I also considered the electric motors but didnt like the idea of fitting a battery and solar cell etc and the thrust from them is incredibly low.
Since we have aspirations of more coastal exploration Ive ended up buying a secondhand 4hp 2-stroke 2 cylinder Johnson seahorse (exactly the same as the evinrude equivalent.) It weighs a fraction more than the Seagull but is massively more poweful and much quieter ( although obviously not as quiet as a Honda ) will still run on one cylinder at reduced power output in an emergency and the short shaft version puts the prop far enough back that theres no possibility of dinging the rudder and the self-contained starter cord is fab. At 50:1 fuel/oil mix its not too smokey and the smooth outer casing is much less likely to tangle up the main sheet than the Seagull. Overall for just over £100 including a full service I reckon its a good little motor and suits me.